The invention relates to new and useful improvements in airport engineering. More particularly, the invention relates to a switch-off device for series circuits at airports, having input terminals which are connected to a current source, output terminals which are connected to an airport series circuit, and connecting elements by means of which the input terminals and the output terminals can be connected to one another. Examples of series circuits at airports, to which the present invention is applicable, include runway and taxiway lights, stop bar lights, and aircraft sensors and detectors.
In existing devices of such type, it is necessary for a plug which connects the current source and the series circuit to be withdrawn from its holding device. Two operating states are defined: first, a state in which the plug is seated inside the holding device provided for it and second, a state in which the plug is withdrawn from the holding device. These states correspond respectively to a normal state, in which the series circuit is connected to the current source and a non-operational state, in which the series circuit is disconnected from the current source. When such a plug is withdrawn, conductors suitable for conducting current are exposed. This can pose risks in particular to the operating and maintenance personnel who come in contact with the switch-off device. A more detailed description of such an existing device is found, e.g., in the ADB brochure "Series Plug Cutout", 2/04.87, which is hereby incorporated into the present application by reference.